Centrifugal pump



Patented May 29, 1923.

UNETE STATES PATENT FFHE.

JOHN D. NOLAND, OF MEMPHIS, TEN NESSEE, ASSIGNOR TO LAYNE AND BOW'LER COMPANY, OF MEMPHIS, TENNESSEE,A CORPORATION OF TEXAS.

GENTRIFUGAL PUMP.

Application filed August 22, 1921.

T 0 all whom it may concern:

Be itvknown that I, Join: D. NoLANn, a citizen of the United States, and a resident of Memphis, in the county of Shelby and State of'Tenness'ee, have invented certain new and useful Improvements in Cent-rifugal Pumps, of which the following is a specification.

This invention relates to centrifugal pumps, and is particularly directed to that type of pump which is generally utilized for pumplng water or other liquid fromrelatively deep wells and in which the water is elevated by centrifugal action through the operation of a rotary runner operating in a stationary pump bowl, and further the invention is especially directed to apump in which the runner imparts velocity to the water and'directs it in a plane approximately at right angles to the axis of rotation and into a stationary pump bowl which conducts the water in a direction approximately axial relative to the shaft.

The object of the invention is to provide a pump of the above character in which the pump runner and the water ways through the bowl are coordinately proportioned to impart to each portion of the body of water flowing through the runner a velocity proportionate to its travel through its change of direction in the bowl,so as to produce a free smooth flow of maximum volume and velocity and to eliminate conflicting velocity influences such as tend to produce detrimental back pressures retarding the discharge; to provide a pump in which the maximum degree of velocity derivable from centrifugal, action is utilized; and to provide a pump in which the hydraulic load ordown thrust is reduced to a minimum.

Various other objects and advantages will be'more fully apparent from the following description of the accompanying drawings,v

which form a part of this disclosure and which illustrate a preferred form of embodiment of the invention.

Of the drawings:

Figure 1 is a vertical section through a two stage pump embodying the presentinvention;

Figure 2 is a diagram illustrating the manner in which water flows through a pump of the ordinary structure heretofore em loyed; and

igure 3 is a similar diagram illustrating Serial No. 494,320.

In a two stage pump, such as is illus= i trated in the drawing, the lower bowl directs the water to the runner of the upper unit, each unit stepping up the velocity of the'water. It will be understood that the number of such units comprising a complete pump may be varied as desired.

Referring to the drawings, each unit comprises a stationary pump bowl 1 having water ways 2.which receive the water from the centrifugal pump runner 3 and conduct the water approximately axially relative to the drive shaft 4, the runner being keyed or otherwise secured to the shaft to rotate therewith. The runner comprises an upper wall or shroud 5. a lower Wall or shroud 6, and intermediate vanes or webs 7 providing independent water passages 8.

By a rotation of the runner a relatively high velocity is imparted by centrifugal action to the water flowing through the passages 8, the water discharging from said passages 8 into the water ways 2 of the stationary bowl 1 where its direction of ways 2 to conduct the water approximately axially relative to the shaft.

It will be particularly pointed out that the upper wall or shroud 5 of the runner is of less diameter than is the lower wall or shroud 6, and that the vanes or webs 7 extend fiush' with the peripheries of both shrouds. 'This provides a runner having a peripheral edge angled relative to the plane of its water passages whereby a greater velocity is imparted to the water adjacent the lower shroud than is imparted to the water adjacent the upper shroud with the velocity of the intermediate portion of the flow varying between these two extremes. This form of runner is provided to produce a free smooth fiow of the water through the inlet end of the water ways 2 where the direction of the flow is changed'from approximately horizontal to approximately vertical, as will now be explained by comparison with the action in a runner havin shrouds of equal diameter and vertical peripheral edges.

In Figure 2, the action of the Water in a pump having shrouds of equal diameters is illustrated in diagram. In this instance, the fluid flowing from the runner at a; has the same velocity as that flowing from the runner at y, the effect being that the fluid m will be forced across the water way 2 and will interfere with the clean sweep of the fluid y in its'travel around the curve m, creating a back pressure at z and a greatly retarded flow around the curve n.

I my improved pump the peripheral edge of the runner is angled coincident to the difference in length of the curves m and n so that the velocity of the fluid leaving the runner at y (see Figure 9 is proportionately greater than the-velocity of the fluid leaving the runner at w, as the length of the curve m is greater than the length of the curve n, this causing all of the molecules of the fluid to reach the zone to at the end of the curve, at the same time.

This construction provides a pump in which the speed of the water at the discharge point of the runner varies from a mlnimum at the upper wall 'or shroud to a maximum at the lower wall or shroud in the same ratio as the length of the outer curve m is greater than the length of the inner curve n. Therefore, it will be evident that the change of direction of the water is effected with a minimum degree of shock or disturbance to the free smooth flow of the water and with a minimum loss of velocity. Further, in my pump I have eliminated such conflicting velocity influences as tend to retard the flow and increase the hydraulic down thrust, and at the same time utilize the maximum propelling effect of centrifugal action.

It is well understood that to utilize the full propelling effect of centrifugal-action in a pump of this character the passages in the pump runner must extend in a plane at right angles to the axis of rotation, and that any deviation from such right angled plane will lessen the velocity imparted by centrifugal action and increase the hydraulic load on the pump runner. Therefore, it will be evident to those skilled in the art that I have retained the full centrifugal efliciency of a runner discharging at right angles to the axis of rotation and have made provislons for effecting a change of direction of the flow without materially reducing the velocity and volume of discharge.

To the best of my knowledge, I am the first to discover that in a pump having a runner propelling the fluid in a plane at right angles to the axis of rotation, and discharging the fluid in stationary water ways formed to conduct the fluid around an approximately right-angled curve, the conflicting velocity influences illustrated in Figure 2 will be eliminated by angling the peripheral edge of the runner from adjacent the outer curve of the water ways inwardly to a point adjacent the inner curve of said water ways to a degree directly proportionate to the difference between said inner and outer curves, so that the velocity of the fluid traveling around the greater curve of the water ways will be proportionately greater than that of the fluid traveling around the less curve thereof as the length of the greater curve is greater than the length of the less curve, this causing all of the molecules of the fluid flowing through the curved water ways in a change of direction of the flow to arrive at the end of the curve at the same time.

With the above described structure I have produced a pump which by actual test gives a ten per cent greater step up per unit with a thirty-eight per cent less hydraulic down thrust and which requires seven per cent less driving power than a pump of the same proportions having a runner with straight peripheral edges such as designated in Figure 2 of the drawings.

In the ordinary types of runners which discharge the water in an upwardly angled direction the upper shroud may be of less actual diameter than the lower shroud, due to the angular disposition of one or both shrouds, but in such runner construction the Water is directed upwardly in the runner passages with a proportionate loss in centrifugal efliciency and a resultant loss in velocity. Further the hydraulic load will more directly counteract the centrifugal action in such angled discharge runner than in runners having a horizontal discharge. In contradistinction in my improved construction the water passes through the runner passages in a plane at right angles to the shaft at a high velocity derived by a maximum utilization of centrifugal action, and is subsequently given its entire upward turn in the stationary bowl of the pump. This, coupled with the coordinate proportioning of the runner and the water way in the stationary bowl makes it possible to impart to the water a maximum velocity by centrifugal action and to subsequently change its direction of flow without shock and without creating retarding back pressure or eddying.

As the elevation of the water depends entirely upon velocity induced by centrifugal action, the efliciency of a pump depends upon a maximum utilization of centrifugal action and the elimination of such counteracting influences as tend to retard the velocity derived therefrom, \Vith this fact in mind it will be evident that in my impro. ed pump a maximum centrifugal efficiency and is water without creating a resultant high velocity is obtained by providing a runner discharge at right angles to the axis of rotation whereby the upward turning of the water is effected entirely in the stationary bowl of the pump, and that by definitely and coordinately proportining the runner and the stationary waterways I have effected a change of direction of the back pressure, shock, or conflicting water currents.

I claim as my invention:

1..In a centrifugal pump, the combination, with a pump bowl provided with water ways for conducting fluid around an approximately right-angled curve, of a drive shaft journaled to rotate in the pump bowl, and a centrifugal runner secured to the shaft and rotatable within the pump bowl, said runner having fluid passages in a plane at right angles to the axis of rotation and formed with the periphery of the runner at the point of discharge of the fluid passages angled proportionately to the curve of the water ways.

2. In a centrifugal pump, the combination, with a pump bowl provided with Water ways for conducting fluid around an approximately right-angled curve, of a drive shaft journaled to rotate in the pump bowl, and a centrifugal runner secured to the shaft and rotatable within the pump bowl, said runner having an upper shroud, a lower shroud and intermediate webs extending to the peripheries of both shrouds, the shrouds and webs defining fluid passages in a plane at right angles to the axis of rotation andithe lower shroud bein of greater diameter than the upper shroud 1n the same proportion as the greater curve of the right-angled curved water ways is longer than the less curve thereof.

Signed at Memphis, day of August, 1921. JOHN D. NOLAND.

v lVitnesses S. G. GORDON, J12, J. M. SINCLAIR.

Tennessee, this 18th 

